Once "The Standard of the World," by the early 1980s GM's Cadillac division had nose-dived to "The Standard Engine on Our New Cimarron Is a Four-Cylinder." Cadillac has since scrambled back to become "Another Legendary Automaker Attempting To Reestablish Past Glory." But give the Wreath-and-Crest brand credit for aiming high. With Bavaria's BMW proffering a 500-horsepower, V-10-propelled Motorsport Division version of its 5 Series sedan, Cadillac has unveiled a new, second-generation CTS-V that wouldn't look out of place alongside a crate of TNT.

Clearly, Motown 2.0 was asking for this matchup against Munich.

Dimensionally, M5 and CTS-V are near-mirror reflections, within fractions of each other in length, wheelbase, width, and height. By those mere fractions, the BMW is the larger car, but it doesn't tip the scales accordingly. In fact, aided by its high-strength aluminum chassis, it's 183 pounds lighter than the CTS-V.

Leaving aside debates about the relative merits of the Cadillac's creased-envelope styling versus Chris Bangle's baroque E60 M5, there's a clear distinction in the Motown and Munich approaches to supersedan elegance. The Munich way is subdued and muted, with little exterior adornment and a neatly tailored cabin of matte-finish materials. The Motown way, in contrast, is all flash and Yankee Doodle dandy, the product of designers and marketers who equate "deluxe" with "shiny." Not a piece of trim or a ring of instrument escapes the Vegas patina. Thus, the understated M5 looks and feels far more expensive (and, at a base price of $89,325 including guzzler tax, it is -- almost shockingly so). The CTS-V starts, with guzzler, at $60,700. Brush away the glitter and the Caddy would look far richer.

Both cars wear enormous, ventilated disc brakes at each corner (the M5's discs are cross-drilled; the Caddy wears six-piston Brembos up front, four-piston in back), and the 19-inch alloys on both are shod with the same Michelin Pilot Sport PS2 performance tires. Computerized variable suspensions grace both sedans, too: The BMW uses the latest iteration of the maker's three-mode (comfort, normal, sport) Electronic Damper Control, while the Cadillac boasts Delphi's brilliant MagneRide shocks.

Under their hoods, both M5 and CTS-V shiver with muscle, but here their recipes differ dramatically. The BMW's mill is the product of a Formula 1 clean room, a 5.0-liter V-10 fortified with a throttle body for each cylinder and an 8250-rpm redline -- enough for 100 horsepower per naturally aspirated liter (and 383 pound-feet of torque). The CTS-V will have none of that exotica. Its engine is, essentially, a "lite" version of the LS9 in the Corvette ZR1, though it's about the weightiest "lite" you'll ever see. Ahead of the firewall lie 6.2 supercharged liters of V-8, good for 556 horsepower and 551 pound-feet -- and possibly a nod to power the next Space Shuttle.

Though automatics are available with both sedans (the CTS-V's is a conventional six-speed slushbox with paddles, the M5's a seven-speed sequential manual), we ordered both test cars with six-speed manual boxes. The Caddy's manual shifter is the same Tremec TR-6060 used in the ZR1.

If the two sedans seem close on paper -- nearly the same size, the BMW less potent but the Caddy heavier -- at the track they proved even more so. With an aggressive clutch drop and all stability electronics turned off, the M5 stormed to 60 mph in just 4.1 seconds (the car might have been a tick quicker, but a rear sensor designed to protect the diff by monitoring wheelhop dulled the throttle for a blink). The CTS-V, by just 3800 rpm unleashing all 551 pound-feet upon the rear tires, required a more judicious foot at launch but managed an even quicker sprint to 60: just 4 seconds flat. That advantage extended only slightly in the quarter mile, the M5 running in 12.5 seconds at 115.3 mph, the CTS-V needing just 12.3 seconds at 117.0 mph. What the numbers don't reveal is just how heroic these sedans are in action, each one chirping the tires through third gear, the M5's exhaust a searing scream, the Cadillac's the deep, stentorian bellow of some almighty creature caged up on Olympus.

In our figure-eight test, the Caddy again edged its Bavarian target, circling in 25.2 seconds versus the M5's 25.8. After that, you'll practically need a microscope to tell the two apart: Both brake to a stop from 60 mph in only 109 feet, and maximum grip is nearly the same, 0.92 g for the Cadillac, 0.90 for the BMW.

Cadillac's new CTS-V currently holds the record (with a time of 7:59.32) as the fastest production sedan on stock tires around the Nurburgring Nordschleife. Naturally, for this comparison we added hot laps to our usual testing regimen. Though our road course at the Emergency Vehicle Operations Center (EVOC) near San Bernardino, California, was no Nordschleife (laps times were just under one minute), the mix of straights, very tight turns, and quick sweepers nonetheless provided a revealing look at the distinctly different personalities of the M5 and CTS-V.

The BMW proved a surprise into the very first corner. The front end doesn't bite as you expect a BMW to do, and steering feel is lacking (hard to believe that the pushy M5 is in any way related to the brilliantly responsive M3). In compensation, the rear end resolutely locks onto the asphalt, even with traction control off. (Though the M5 operates in "P400" daily driving mode by default, delivering 395 SAE horsepower, by programming the M Driving Mode system via the iDrive controller, the driver can select P500 mode -- all 500 horses -- or P500 Sport, for full power and quicker throttle response. We ran our hot laps in P500 Sport with stability and traction controls off.) Accelerating through a fast, tricky left-right sweeper, the M5 never so much as slipped a wheel. Best lap time: 58.5 seconds.

The CTS-V behaves like a 180-degree M5. Its front end delivers gobs of grip, and steering feel is exemplary; turn-in is quick and satisfying. Its rear end, though, will head for the North Pole at the slightest overindulgence of throttle (though the car's StabiliTrak system offers normal and Competitive modes, we again lapped with all chassis electronics switched off). It's all torque-flooded, tail-happy grins, yes, but take care not to get carried away. Through the same sweeper that the M5 negotiated like a slot car, the CTS-V readily stepped sideways -- in third gear. It takes determination to keep that ferocious ZR1 motor from getting the upper hand, but the Caddy's power and grip advantages pay real dividends. Best lap time: 58.1 seconds.

For fun, we ran the same road course in a new Lotus Exige S 260. It clocked a 57.0. Think about that for a moment. Two four-door sedans, loaded with leather, navigation systems, premium audio, power everything, sunroofs, trunks, etc., clock lap times barely a second and a blink off a purebred, 2032-pound, two-seat sports car with all the creature comforts of a jail cell. Also, golf clubs look silly on the rear wing of the Lotus.

Priced at $94,895 as-tested, the BMW M5 says "premium" from the bottom line on its window sticker to the velvety feel of its controls to the secure embrace of its sport seats. The CTS-V can't match the BMW for fit and finish (one example: when raising the driver-seat headrest, the anchor plugs pulled out of the seat back), and it's simply not as finely matured as its Bavarian rival. Even at $3400, the CTS-V's optional Recaro front buckets can't compare with the BMW's thrones for holding you in place when driving hard (the Caddy's $300 suede wheel is a nice touch, though). Then again, at $67,540 as-tested the Cadillac undercuts the BMW by nearly $30 grand. For its lofty admission price, the BMW had BETTER be built like a Tiffany clock.